The present invention relates to a coolant fill housing for a vehicle coolant system. More particularly, the present invention relates to a coolant high fill housing for the coolant system of the vehicle which provides a revised fluid flow path and which includes an integrally mounted thermostat for controlling fluid flow through the vehicle coolant system.
As automotive industry design trends dictate a lower front end profile for vehicles, it becomes necessary for the radiator of the vehicle to be mounted below the highest point of the engine. In this instance, there is a need for a fill point at a location higher than the radiator in order to insure complete filling of the coolant system. This high fill point is typically located at the coolant outlet of the engine. Therefore, a high fill housing is provided to permit an operator to fill the coolant system of the vehicle with fluid. The present invention provides a coolant fill housing which includes an integrally mounted thermostat and a radiator cap to provide system closure, control fluid flow, and regulate the pressure of the coolant system.
Advantageously, the present invention provides a unique coolant fill housing and thermostat design that provides a single fully functional part of the coolant system, including the fill housing, radiator cap, and thermostat. Providing the coolant fill housing with an integral thermostat reduces parts and overall labor and material cost. In addition, providing an integral thermostat eliminates the possibility of inserting inverted thermostats in automobiles. Advantageously, testing of a complete radiator cap and thermostat system can be combined prior to shipment in the coolant fill housing of the present invention.
Another feature of the present invention is the provision of venting through the coolant fill housing with the integral thermostat mounted therein. A vent channel allows air passage when fluid flow enters the coolant system from the radiator side such as in the case of a forced fluid fill into the fill housing. Air passes through the vent channel and eliminates air entrapment. Fluid pressure from the engine side of the coolant system closes a valve in the vent channel to restrict fluid flow through the vent channel.
Yet another feature of the present invention is the provision of an integral thermostat and coolant fill housing with a controlled fluid flow feature. The apparatus of the present invention uses weir channels formed in the housing adjacent the thermostat valve. The design of the present invention allows a moderate flow of fluid to escape through the weir channels as the thermostat valve begins to open. This moderate initial fluid flow eliminates a sudden surge of coolant that often occurs when a typical thermostat is used to control fluid flow. For other examples of references including weirs, see U.S. Pat. Nos. 4,053,105; 4,164,332; and 4,286,750.
Still another feature of the present invention is the provision of means within the coolant fill housing for reducing the pressure in the coolant fill housing adjacent a fill section of the housing. In the illustrated embodiment, a venturi is located within a main flow path of the fill housing to generate a low pressure area or pressure drop immediately down stream from the venturi. The pressure decreases proportionally as engine coolant flow through the fill housing increases. By locating the venturi adjacent the fill section of the fill housing, the radiator cap which closes off the fill port is subjected to the lower pressure as fluid flows through the fill housing. This reduced pressure offsets the increased pressure generated by pump discharge flow and radiator core restriction and allows the system to function properly at all discharge flow rates.
According to one aspect of the present invention, an apparatus is provided for filling an engine cooling system with coolant fluid and for controlling fluid flow through the cooling system in response to changes of an engine or system coolant temperature. The apparatus includes a fill housing having an inlet section, an outlet section, and a fill section configured to receive a cap thereon. The inlet section is formed to include a valve seat and a flange for coupling the fill housing to an engine. The apparatus also includes a thermostat and means for coupling the thermostat to the flange to hold the thermostat within the inlet section beneath an outer surface of the flange.
In the illustrated embodiment, the thermostat includes a movable valve member for engaging the valve seat of the fill housing to block the flow of fluid past the valve member and into the inlet section, a retaining frame coupled to the flange for holding the thermostat within the inlet section beneath the outer surface of the flange, and a spring extending between the retaining frame and the movable valve member for biasing the movable valve member to a normally closed position against the valve seat. The retaining frame is preferably coupled to the flange by a bayonet attachment to hold the thermostat in the inlet section of the fill housing beneath the outer surface of the flange. The thermostat also includes a thermally responsive actuator coupled to the movable valve member for moving the movable valve member to an open position away from the valve seat when the ambient temperature exceeds a predetermined temperature to permit fluid flow from the engine into the inlet section of the fill housing.
Also in the illustrated embodiment, the thermally responsive actuator of the thermostat includes a stem portion and a power element. The fill housing includes an internal rib positioned in the inlet section downstream from the valve seat for supporting the stem portion. The internal rib is formed integrally with the fill housing. The internal rib and the fill housing may be made from a plastic or other suitable material.
In one illustrated embodiment, the fill housing is formed to include a weir channel adjacent the valve seat to permit fluid flow through the weir channel as the valve member moves away from the valve seat. In another embodiment, the fill housing is formed to include a vent channel and a valve located in the vent channel. The vent channel includes an enlarged portion, and the valve includes a ball located in the enlarged portion to open and close the vent channel. The apparatus further includes a flexible lip portion formed adjacent the enlarged portion of the vent channel to permit the valve ball to be inserted into the enlarged portion of the vent channel.
According to another aspect of the present invention, a fill housing apparatus is provided for filling an engine cooling system with coolant fluid. The apparatus includes an inlet section, an outlet section, and a fill section configured to receive a removable cap thereon to permit coolant fluid to be added to the cooling system. The apparatus also includes a venturi portion located between the inlet section and the outlet section to provide a pressure drop inside the fill housing as fluid flows through the fill housing.
In the illustrated embodiment, the outlet section is aligned at an obtuse angle relative to the fill section to reduce fluid flow into the fill section as fluid flows from the inlet section to the outlet section of the fill housing. The venturi portion is located adjacent the fill section to subject the fill section to the pressure drop as fluid flows through the fill housing.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.